On August 10 -- two days after she gave birth to a 7 lb., 9 oz. baby boy named Camden Jack -- the former reality star took to Twitter to share her baby joy. "Being a mom is the most incredible feeling," she wrote. "I am so in love with this little boy!"

This is the first child for Cavallari, 25, and her Chicago Bears quarterback fiance, Jay Cutler, 29. Following a brief split in July 2011, the pair reconnected fourth months later. They announced they were expecting in January 2012.

In the days following her son's birth, several of Cavallari's former "Hills" costars have sent her congratulatory messages via Twitter. "Can't wait to see Camden," Audrina Patridge, 27, said. "So happy for you!"